Hi @CAROLE,
Welcome to the forum 
: Will do my best to try and help you.
It does sound like you’re having the same issue as in this other topic: How to provide passphrase in SSL/TLS certificates - OSS Support - k6 community forum. If that’s indeed the case, k6 still doesn’t have native support for what you’re trying to do, but as pointed in this topic, there might be some workarounds worth trying.
Let me know if that’s helpful and if I can support you further! 